研究室工作进展 Aug. 8th, 2016
Direct Synthesis of Phospholyl Lithium from White Phosphorus
Ling Xu, Yue Chi, Shanshan Du, Wen-Xiong Zhang,* and Zhenfeng Xi
Angew. Chem. Int. Ed. 2016, 55, 9187-9190.
Selective construction of P?C bonds directly from P4 and nucleophiles is an ideal and step-economy approach to utilize elemental P4 for straightforward synthesis of organophosphorus compounds. In this work, highly efficient one-pot reaction between P4 and 1,4-dilithio-1,3-butadienes is realized, affording phospholyl lithium derivatives quantitatively. DFT calculation indicates that the mechanism is significantly different from that of the well-known stepwise cleavage of P?P bond in P4 activation. Instead, a cooperative nucleophilic attack of two Csp2?Li bonds on P4 leading the simultaneous cleavage of two P?P bonds is favorable. This understanding of the mechanism offers a new view on the mechanism of P4 activation as well as a reasonable explanation on the excellent yields and selectivity. This methodology demonstrates a prospective route for P4 activation and consequent production of organophosphorus compounds.
亮点介绍
从白磷到有机膦化合物的传统合成路线复杂而冗长，绝大部分情况下都涉及到剧毒、强腐蚀、易燃（如PCl3, PCl5, PH3）等反应条件并对环境造成巨大污染。从白磷出发直接高效高选择性合成有机膦化合物是一个理想的方法，受到人们的关注。最近，我们利用丁二烯基桥联的双锂试剂与白磷直接反应，在温和的条件下高产率制备了磷杂环戊二烯的锂盐。双锂试剂的两个锂，如同挖掘机的铲斗，直接从白磷的四个磷原子中“铲走”一个磷形成磷杂环戊二烯的锂盐。这种双金属试剂直接与白磷反应，一步高效构建有机膦化合物的新方法为白磷高效利用提供了新思路。